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A126613 a(1)=1. a(n) = a(n-1) + (number of terms, from among terms a(1) through a(n-1), which are powers of primes {including 1}). 0

%I

%S 1,2,4,7,11,16,22,28,34,40,46,52,58,64,71,79,88,97,107,118,129,140,

%T 151,163,176,189,202,215,228,241,255,269,284,299,314,329,344,359,375,

%U 391,407,423,439,456,473,490,507,524,541,559,577,596,615,634,653,673,694

%N a(1)=1. a(n) = a(n-1) + (number of terms, from among terms a(1) through a(n-1), which are powers of primes {including 1}).

%e There are 7 prime powers (1,2,4,7,11,16,64) among the first 14 terms of the sequence. So a(15) = a(14) + 7 = 71.

%t a = {1}; Do[AppendTo[a, a[[ -1]] + 1 + Length[Select[a, Length[FactorInteger[ # ]] == 1 &]]], {60}]; a (* _Stefan Steinerberger_, Oct 16 2007 *)

%Y Cf. A131073.

%K nonn

%O 1,2

%A _Leroy Quet_, Jun 13 2007

%E More terms from _Stefan Steinerberger_, Oct 16 2007

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Last modified August 11 18:17 EDT 2020. Contains 336428 sequences. (Running on oeis4.)